Root Vegetable Gratin

A colorful, cozy fall gratin layered with sweet potato, beet, and parsnip, all tossed in garlicky cream and finished with plenty of Parmesan and Gruyère.

Ingredients

• 2 large sweet potatoes, peeled + thinly sliced

• 2 medium beets, peeled + thinly sliced

• 3–4 parsnips, peeled + thinly sliced

• 1½ cups heavy cream (or cream + whole milk)

• 3 garlic cloves, minced

• 1 Tbsp thyme leaves, plus more for topping

• 1 cup grated Parmesan

• 1½ cups grated Gruyère

• Salt

Instructions

1. Prep the oven + vegetables

• Heat oven to 375°F.

• Thinly slice the sweet potatoes, beets, and parsnips with a mandolin or sharp knife.

• Place each sliced vegetable into its own bowl.

2. Make the cream mixture

• In a separate bowl, whisk together:

  • heavy cream

  • 3 cloves garlic

  • most of the thyme

  • a pinch of salt

3. Coat the vegetables

• Divide the cream mixture evenly among the three bowls of vegetables.

• Toss each bowl gently so every slice is lightly coated (this helps flavor every layer and prevents dryness).

4. Build the gratin

• Grease a baking dish.

• Layer the vegetables in a repeating pattern:
  sweet potato → beet → parsnip → repeat.

• As you layer, sprinkle Parmesan throughout.

5. Add the Gruyère

• Sprinkle 1½ cups grated Gruyère evenly over the top.

6. Bake

• Cover with foil and bake 30 minutes.

• Uncover and bake another 20–25 minutes, until the top is golden and bubbling.

7. Finish

• Let rest a few minutes.

• Top with fresh thyme.

• Serve warm.